GOALI: Novel Thin Film Composite Membranes for Desalination by Forward Osmosis

1067564McCutchen日益干旱的世界需要创新可持续的技术，从受损的和咸水的水源中生产饮用水。现有的海水淡化技术，如反渗透(RO)，由于高昂的能源成本和对环境有害的盐水排放，仍然是一个不可持续的选择。正向渗透(FO)是一种创新和可持续的海水淡化替代方案，有望从根本上降低成本、能源消耗和盐水排放，从咸水水源提供饮用水。与需要液压驱动力进行分离的RO不同，FO利用由拉伸液产生的渗透驱动力。FO的新奇之处在于使用了NH3-CO2盐作为抽出溶质。PI和co-PI鉴定这些盐的原因是它们的渗透效率(能够产生高达3,000磅/平方英寸或7,000英尺头的渗透压)，并且只使用低品位的废热(低至40°C)即可轻松移除和重复使用。FO技术成功商业化的唯一障碍是，由于存在严重的传质限制，即内部浓差极化，现有的除盐膜的生产能力很低。康涅狄格大学(UConn)和Oasys Water TM(Oasys)正在共同努力，通过考虑革命性的薄膜复合(TFC)膜设计来实现这一变革性技术，以减轻这种削弱现象的影响。创新的关键技术领域由PI和co-PI在之前的努力中确定，重点是使膜支撑结构更薄、更多孔和更少的曲折。这项拟议的工作考虑将电纺纳米纤维非织造布作为新一代TFC膜的新型支撑结构，这些TFC膜是为NH3-CO2正向渗透量身定制的。静电纺丝是一种常用的方法，用于制造高孔、薄的纳米纤维非织造材料。该项目是首次尝试将这种具有可调特性的独特结构应用于FO应用的TFC膜。纳米纤维非织造布将用于锚定由间苯二胺原位聚合沉积的交联型聚酰胺阻隔层。将对生成的TFC膜进行表征，并对其通量和选择性性能进行评估。PI开发的FO通量模拟技术将用于确定内部浓差极化的严重程度，并为未来的膜设计迭代提供输入。这项工作将首次使用电纺纳米纤维非织造布作为为FO量身定做的TFC膜的支撑结构。这项工作将进一步使FO这一新兴的膜技术实现承诺的结果，即更低的水成本和更高的回收率。在实验室中构建这些膜将需要一种综合的方法，该方法将考虑电纺支撑件制造和聚酰胺选择性层形成的所有方面，因此需要聚合物科学、纳米技术和质量传输方面的独特专业知识的结合。该项目还将导致对支撑层结构如何影响原位聚合过程和所得薄膜性能的基本了解。PI和共同PI都被认为是FO方面的世界专家，是唯一适合完成这项拟议工作的人。两者都可以使用专门为本提案中概述的任务量身定做的设施和专业知识。这个新兴的技术平台将成为康涅狄格州大学学生的优秀教育工具。正向渗透是一个多步骤的过程，它依赖于几个单元的操作。因此，我们将专门将正向渗透技术整合到化学工程Capstone高级设计课程中，让多个团队有机会竞争使用最少能源和最低资本成本的最佳设计配置。Oasys将对这一努力感兴趣，该公司将赞助一个针对康涅狄格州大学工程专业学生的实习计划，该计划将促进康涅狄格州大学工程师的就业，并促进长期的学术-产业合作伙伴关系。在21世纪，安全和可持续的供水是人类在公共卫生方面面临的最艰巨的任务。我们必须通过使用FO等可持续和负担得起的技术处理受影响的水源来增加我们现有的水供应。这些问题在任何地方都比在发展中国家更相关。因此，PI将与无国界工程师(EWB)康涅狄格州大学分会合作开展一个独特的项目，在埃塞俄比亚安装商用FO系统，作为远程净水器和教学工具。这一努力将是通过康涅狄格州大学实施的现有美国国际开发署/高等教育机构(US-AID/HED)项目的一部分。

1067564McCutcheonAn increasingly arid world requires the innovation of sustainable technologies to produce potable water from impaired and saline water sources. Existing desalination technologies, like reverse osmosis (RO), remain an unsustainable option due to high energy costs and environmentally harmful brine discharges. Forward osmosis (FO) is an innovative and sustainable desalination alternative that promises to provide potable water from saline water sources at radically reduced cost, energy consumption, and brine discharge. Unlike RO, which requires a hydraulic driving force for separation, FO utilizes an osmotic driving force generated by a draw solution. The novelty of FO lies in the use of NH3-CO2 salts as a draw solute. These salts were identified by the PI and co-PI for their osmotic efficiency (capable of generating osmotic pressures up to 3,000 psi or 7,000 ft of head) and easy removal and reuse using only low grade waste heat (down to 40°C). The single obstacle to the successful commercialization of FO technologies is the poor productivity of existing salt-rejecting membranes due to a severe mass transfer limitation known as internal concentration polarization. The University of Connecticut (UConn) and Oasys WaterTM (Oasys) are combining their efforts to enable this transformational technology by considering revolutionary thin film composite (TFC) membrane designs that will mitigate the effects of this debilitating phenomenon. Key technical areas of innovation, identified by the PI and co-PI in previous efforts, are focused on making the membrane supporting structure thinner, more porous and less tortuous. This proposed work considers the implementation of electrospun nanofiber nonwovens as novel support structures in next generation TFC membranes tailored for NH3-CO2 forward osmosis. Electrospinning is a method that is commonly used to create highly porous and thin nanofibrous nonwoven materials. This project is the first effort to apply this unique structure with tunable properties in TFC membranes for FO applications. The nanofiber nonwoven will serve to anchor a crosslinked polyamide barrier layer deposited by in situ polymerization of m-phenylenediamine. The resulting TFC membranes will be characterized and evaluated for flux and selectivity performance. FO flux modeling techniques, developed by the PI, will be used to determine the severity of internal concentration polarization and provide input for future iterations of membrane design. This effort will for the first time employ an electrospun nanofiber nonwoven as a support structure for a TFC membrane tailored for FO. This work will further enable FO, an emerging membrane technology, to deliver on promised results of lower water cost and higher recovery. Constructing these membranes in the laboratory will require a comprehensive approach that will consider all aspects of the electrospun support fabrication and polyamide selective layer formation, thus requiring a unique combination of expertise in polymer science, nanotechnology, and mass transport. This project will also result in fundamental understanding of how the support layer structure impacts the in situ polymerization process and the performance of the resulting film. The PI and co-PI, both considered world experts on FO, are uniquely suited to complete this proposed work. Both have access to facilities and expertise that are customized specifically for the tasks outlined in this proposal. This emerging technology platform will serve as an excellent educational tool for students at UConn. Forward osmosis is a multistep process which relies on several unit operations. We will thus specifically integrate forward osmosis into the Chemical Engineering capstone Senior Design Course, giving multiple groups an opportunity to compete for the best design configuration which uses the least energy and has the lowest capital cost. This effort will be of interest to Oasys, which will sponsor an internship program for UConn engineering students that will facilitate the employment of engineers from UConn as well as foster a long term academic-industrial partnership. A safe and sustainable water supply in the 21st century is the most daunting task humanity faces with regards to public health. We must augment our existing water supplies through the treatment of compromised sources with sustainable and affordable technologies like FO. Nowhere are these issues more relevant than in the developing world. The PI will thus embark on a unique project in collaboration with the UConn chapter of Engineers without Borders (EWB) to install commercial FO systems in Ethiopia as remote water purifiers and teaching tools. This effort will be part of an existing US Agency for International Development/Higher Education (US-AID/HED) project conducted through UConn.